All Hallow's Eve.

Sanctum Sanctorum - All Hallow’s Eve (by Hiyomi Mokusei)

The Headless Horseman rides again at Sanctum Sanctorum…Beware!

For those of you who may be unfamiliar with the fictional short story from 1820 by Washington Irving, the Headless Horseman was the ghost of a Hessian soldier, a mercenary who worked for the British Army during the Revolutionary War. His head was blown off by a cannonball while fighting near the town of Sleepy Hollow in the state of New York. Forever after, his spirit was said to haunt the area near the town.

It was said that no one dared venture out on a certain road at night, or he would chase you down on his huge black steed, and take your head. This is the assumed fate of the main character Ichabod Crane, when he took a chance one night, trying to get home, and was subjected to a horrifying chase by the Headless Horseman. No one is certain what happened that night, because his body was never found, but those who believed the legend are sure he met his end at the hands of the Headless Horseman.